U.S. President Donald Trump posted photos of his separate meetings with the top diplomats of Ukraine and Russia on Twitter and urged the two nations to "make peace."

"Yesterday, on the same day -- I had meetings with Russian Foreign Minister Sergei Lavrov and the Foreign Minister of Ukraine, Pavlo Klimkin," Trump tweeted late on May 11 under separate photos of himself smiling broadly by each minister in the Oval Office.

"LETS MAKE PEACE!" he wrote.

Trump held a rare, unannounced Oval Office meeting with Klimkin after a meeting with Lavrov, who earlier on May 10 met with Secretary of State Rex Tillerson at the State Department.

Relations between Moscow and Kyiv have been severely damaged since Russia seized the Crimean Peninsula from Ukraine in March 2014 and fomented unrest in eastern Ukraine, where a war between government forces and Russia-backed separatists has killed more than 9,900 people.

Russia's actions prompted the European Union and the United States to impose sanctions on Moscow. The State Department said that in their meeting, Tillerson told Lavrov that "sanctions on Russia will remain in place until Moscow reverses the actions that triggered them."